Dielectric Properties of Liquid Crystal Polymer Composites with High Thermal Conductivity

Abstract:

Liquid crystal (LC) polymer, composited with inorganic filler, has a broad application prospect in electronic and electrical industry. In this research, permittivity (ε_r) and dielectric loss tangent (tanδ) of LC composites under different temperatures and frequencies were investigated, and activation energies were calculated and analyzed. At low temperatures and high frequencies, LC composites exhibited well dielectric properties. ε_r changed a little (3.6~4.0) in temperature range of-60°C~160°C when frequency was higher than 10Hz, but increased sharply when temperatures was higher than 100°C and frequency was lower 10Hz. The tanδ increased sharply with increasing temperature when temperatures was higher than 100°C and frequency was lower than 10²Hz, and when frequency was above 10²Hz, the value of tanδ changed gently (10^-3~10^-2). The peak of tanδ would translate to higher frequencies direction with increasing temperature in tanδ-frequency curve, and to higher temperatures direction with increasing frequency in tanδ-temperature curve. Activation energy is calculated by fitting the peak of the imaginary of the electric modulus, and activation energy is 0.43eV in low temperature and 1.59eV in high temperature.

• Periodical: Materials Science Forum (Volume 868)
• Pages: 61-67
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.868.61
• Online since: August 2016
• Authors: Peng Fei Gao, Xin Yu, Nai Kui Gao, Teng Yue Ren, Chun Wu, Hai Jin*, Jun-Ichi Matsushita
• Keywords: Dielectric Permittivity, Electric Modulus, Liquid Crystal Polymer, Loss Tangent

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